Resin molded bodies produced from petroleum-based resin such as polyethylene, polypropylene, and polystyrene are used in various fields of fiber products, packaging films, electric appliances, industrial materials, and the like; and they are essential in modern society. However, these resin molded products are used and disposed in large amounts; the disposal of such products is a big problem. For example, there is a problem such that the incineration disposal of the resin molded body generates poisonous gas. Moreover, since petroleum-based resin has hydrolysis resistance, the resin molded body is not biodegraded in soil when disposed in landfills or in fields or mountains, thus resulting in an adverse effect on the environment.
Recently, hydrolyzable biodegradable resin such as polylactic acid is attracting attention as a substitute for petroleum-based resin. When disposed in landfills or in fields or mountains, such biodegradable resin is degraded by microorganisms without destroying the natural environment. The hydrolyzable biodegradable resin is known as an earth-friendly material; however, it is known to have low formability compared to petroleum-based resin. Further, since the biodegradable resin is easily depolymerized by hydrolysis, such resin has poor durability, strength, and heat resistance. Therefore, in the conventional technique, the use of the biodegradable resin in place of petroleum-based resin is limited to specific product fields.
On the other hand, an oxidative degradation agent that depolymerizes a resin material by oxidative degradation has been recently developed (Patent Literature 1). When a biodegradable resin molded body containing such a degradation agent is disposed in landfills or like places, it is depolymerized by oxidative degradation, and thereafter spontaneously degraded through microbial degradation. Since the degradation agent can also be applied to petroleum-based resin having high strength (hydrolysis-resistant material), biodegradability can be attained while keeping the advantages of petroleum-based resin, such as formability, durability, strength, and heat resistance. Thus, the degradation agent is attracting great attention. However, although it is important for waste treated in landfills, etc., to increase the degradation rate to reduce the burden on the environment to the extent possible, a technique of improving the degradation rate of a biodegradable resin molded body containing such a degradation agent has not yet been fully studied.